1. Field of Disclosure
Aspects and embodiments disclosed herein are directed generally to wastewater treatment systems which utilize settling basins and to apparatus and methods for operating settling basins.
2. Discussion of Related Art
Chain and scraper sludge collector equipment is designed to remove settled suspended solids (sludge) from rectangular settling basins, for example, rectangular concrete settling basins, in municipal and industrial water and wastewater treatment plants. In some implementations, rectangular settling basins may be from about 10 feet (3 meters) to about 30 feet (9.1 meters) wide, from about 50 feet (15.2 meters) to about 300 feet (91.4 meters) long, and from about eight feet (2.4 meters) to about 14 feet (4.3 meters) deep. Scraper flights are often used to scrape settled material on the basin floor to a sludge withdrawal location, for example, a hopper in the settling basin. Concurrently with the removal of sludge from the basin floor, other scraper flights may be utilized to push floating material, referred to generally as “scum,” from the surface of liquid in the settling basin to a scum collector for removal.
The sludge and scum removal mechanism in a settling basin often includes two endless strands of chain that run the length of the settling basin. Scraper flights that span the width of the settling basin are mounted to the chain. The chain, and the flights attached to the chain move through the settling basin to direct the sludge to the sludge withdrawal location in the floor at one end of the basin. The chain and flights are propelled by sprockets that are affixed to a headshaft that spans the width of the settling basin.